1. Field of the Invention
The present document relates to a plasma display apparatus.
2. Description of the Background Art
FIG. 1 illustrates a structure of a conventional plasma display panel. As shown in FIG. 1, the conventional plasma display panel is comprised of a front panel 100 and a rear panel 110. The front panel 100 comprises a rear glass substrate 101, and the rear panel 110 comprises a rear glass substrate 111. The front panel 100 and the rear panel 110 are sealed in parallel to be at a predetermined distance.
Sustain electrode pairs 102 and 103 for sustaining light emission of the cell by a mutual discharge are formed on the front glass substrate 101. The sustain electrode pairs 102 and 103 are comprised of a scan electrode 102 and a sustain electrode 103. The scan electrode 102 and the sustain electrode 103 each are transparent electrodes 102-a and 103-a formed of transparent indium tin oxide (ITO) and bus electrodes 102-b and 103-b formed of metal. The scan electrode 102 receives a scan signal for panel scan, and a sustain signal for discharge sustain. The sustain electrode 103 mainly receives a sustain signal. An upper dielectric layer 104 is formed on the sustain electrodes 102 and 103, and limits a discharge current and insulates between the scan electrode 102 and the sustain electrode 103. A protective layer 105 is formed on an upper surface of the upper dielectric layer 104, and is formed of magnesium oxide (MgO) to facilitate a discharge condition.
An address electrode 113 is disposed to intersect with the sustain electrode pairs 102 and 103 on the rear glass substrate 111. A lower dielectric layer 115 is formed on the address electrode 113, and insulates between the address electrodes 13. A barrier rib 112 is formed on the lower dielectric layer 115, and partitions a discharge cell. Red (R), green (G), and blue (B) phosphor layers 114 are coated between the barrier ribs 112, and emit visible rays for displaying an image.
The front panel 100 and the rear panel 110 are coalesced by a sealing material. After the coalescing of the front panel 100 and the rear panel 110, inert gas such as helium (He), neon (Ne), and xenon (Xe) is injected into the plasma display panel.
In the above-constructed conventional plasma display panel, one frame is divided into several subfields to embody an image, and each subfield is divided into a reset period, an address period, and a sustain period.
Meantime, a plasma display apparatus comprises the plasma display panel and a driving device. The driving device comprises a sustain driving circuit for applying an alternating sustain pulse to a scan electrode and a sustain electrode to sustain a discharge of a discharge cell selected in the sustain period.
FIG. 2 illustrates an energy recovery circuit comprised in the conventional plasma display apparatus, and FIG. 3 is a waveform diagram illustrating the sustain pulse of the conventional energy recovery circuit.
A first switch (Q1) turns on and, a second switch (Q2), a third switch (Q3), and a fourth switch (Q4) turn off. Accordingly, energy is supplied from a capacitor (C1) to a plasma display panel (Cp) through resonance. As shown in FIG. 3, a voltage of electrode (Vp) rises from a ground level to a sustain voltage (Vs). The sustain voltage (Vs) is a voltage for sustaining the discharge in the discharge cell selected during the address period.
The third switch (Q3) turns on and, the first switch (Q1), the second switch (Q2), and the fourth switch (Q4) turn off. Accordingly, as shown in FIG. 3, the voltage of electrode (Vp) is sustained to be the sustain voltage (Vs).
The second switch (Q2) turns on and, the first switch (Q1), the third switch (Q3), and the fourth switch (Q4) turn off. Accordingly, energy is supplied from the plasma display panel (Cp) to the capacitor (C1) through the resonance. As shown in FIG. 3, the voltage of electrode (Vp) falls from the sustain voltage (Vs) to the ground level.
The fourth switch (Q4) turns on and, the first switch (Q1), the second switch (Q2), and the third switch (Q3) turn off. Accordingly, as shown in FIG. 3, the voltage of electrode (Vp) is sustained to be the ground level voltage.
In the conventional energy recovery circuit, one inductor (L1) is used for recovering and supplying the energy. In other words, if the inductor (L1) has a great inductance, consumption power reduces and therefore, a driving efficiency of the energy recovery circuit increases but a voltage rise of the sustain pulse is gentle, thereby making it difficult to generate a strong discharge.